Plasma anodization of silicon at room temperature

Abstract Room temperature plasma anodization of silicon (growth rate of a few nm/min.) is possible through a thin calcia stabilized zirconia (CSZ) layer. The anodization kinetics, the composition and the electrical properties of the anodic SiO 2 films are studied. Constant voltage or low current anodization lead to quasi defect free films with reduced surface roughness. The dielectric breakdown field of as grown SiO2 is about 5 x 106 V/cm. The minimum of density of traps at the SiO2/Si interface is in the 1010-1011 cm-2. eV-1 range after hydrogen annealing at 470 °C for 30 min. This is comparable to high temperature (above 400 °C) plasma grown SiO2. The protective filter effect of the CSZ against contamination has also been demonstrated. In addition, thick (above 0.3 μm) SiO2 layers can be obtained in a reasonable time (about 30 min.) at moderate temperatures.